Thiofunctional polysiloxane fluids as well as organopolysiloxane fluids may be prepared by reacting silanes or siloxanes in the presence of acid clays to form thiofunctional polysiloxane fluids and organopolysiloxane fluids. It is known that these siloxane fluids will degrade, especially at elevated temperatures, in the presence of acid clays to form volatile, lower molecular weight siloxanes and odor forming products. This often results in the loss of desirable functional groups and produces lower molecular weight siloxanes.
When blends of siloxane fluids consisting of thiofunctional polysiloxane fluids and organopolysiloxane fluids are used in an electrostatic copying apparatus to effect release between the toner treated paper which is impregnated with kaolin clay and a heated fuser roll, the siloxane fluids have a tendency to degrade and form low molecular weight siloxanes and odor producing products. It is believed that this is due to the kaolin clay which is present in the paper residue that collects in the sump along with the excess release agent. When the sump contents are reused, the combination of acidic kaolin clay and the high temperature of the fuser roll causes the siloxane fluids to degrade to form volatile, low molecular weight siloxanes having reduced functional groups. Condensation of the low molecular weight volatile siloxanes on electrical switches can inhibit the switches function due to the good dielectric properties of the siloxanes.
Therefore, it is an object of this invention to provide stabilized siloxane fluids. Another object of this invention is to provide stabilized blends of thiofunctional polysiloxane fluids and organopolysiloxane fluids. Still another object of the present invention is to provide a process for stabilizing blends of thiofunctional polysiloxane fluids and organopolysiloxane fluids against degradation in the presence of kaolin clay. A further object of this invention is to provide a process for rendering blends of thiofunctional polysiloxane fluids and organopolysiloxane fluids resistant to degradation in the presence of heat and kaolin clay without significantly affecting the properties of the siloxane fluids.